反应详情

3-(5-Tetrazolyl)thioxanthone-10,10-dioxide sodium salt (U.K. patent specification No. 1,447,031; 45.0 g) was stirred and boiled under reflux with 2-normal sodium hydroxide solution for 61/2 hours. The solution was acidified by pouring into excess hydrochloric acid solution and the precipitated product filtered off and recrystallised from dimethylformamide to give the title compound (14.95 g), m.pt. 296° C. (decomposes).

1. filtrationthe precipitated product filtered off
2. customrecrystallised from dimethylformamide